1. Field of the Invention
The present invention relates to an organic electroluminescent device, and particularly, to an organic electroluminescent device which can enhance its contrast by forming the structural element formed on non-emitting area with dark colored black matrix material.
2. Description of the Prior Art
Organic electroluminescence is the phenomenon that excitons are formed in an (low molecular or high molecular) organic material thin film by re-combining holes injected through an anode with electrons injected through a cathode, and light of specific wavelength is generated by energy from thus formed excitons.
FIG. 1 is a plane view of an organic electroluminescent device, and FIG. 2 is a sectional view taken along the line A-A in FIG. 1. These figures schematically illustrate the basic structure of organic electroluminescent device using the above phenomenon.
The basic structure of organic electroluminescent device includes a glass substrate 1, indium-tin-oxide layers 2 (hereinafter, referred as “ITO layer”) formed on the glass substrate 1 and acting as anode electrodes, organic electroluminescence layers 3 formed with organic material, and metal layers 4 acting as cathode electrodes.
The organic electroluminescent device having the above structure is produced through the following processes.
First, the ITO layer is formed on the glass substrate 1 through the vacuum deposition method, and the ITO layer is patterned by the photolithography method to form the ITO electrodes (layers) 2. Then, insulating layers 5a are formed on certain areas of the ITO layers 2, and walls 5 are formed on the insulating layers 2.
Then, the organic electroluminescence layer 3, and the metal layer 4 are formed on the entire structure including the walls 5 in order. Here, the ITO layers 2 disposed on the transparent substrate 1 act as the anode electrodes, and the metal layers 4 act as the cathode electrodes.
As shown in FIG. 1 and FIG. 2, each wall 5 is formed to divide the organic electroluminescence layers 3 and the metal layers 4 into a number of sections. That is, each wall 5 is formed on a space between adjacent two metal layers 4 to separate the metal layers 4, and each wall is separated from the ITO layer 2 through the insulating layer 5a. 
Although the methods for improving contrast of the organic electroluminescent device having the general structure as described above have been discussed and developed, technical development for improving the contrast has been restricted due to the device's structure and the used material's characteristic.